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The discovery of copper dates from prehistoric times. It is said to have been mined for more than 5000 years. It is one of man’s most importantmetals. Copper is reddish colored, takes on a bright metallic luster, and is malleable, ductile, and a good conductor of heat and electricity (second onlyto silver in electrical conductivity). The electrical industry is one of the greatest users of copper. Copper occasionally occurs native, and is found inmany minerals such as cuprite, malachite, azurite, chalcopyrite, and bornite. Large copper ore deposits are found in the U.S., Chile, Zambia, Zaire,Peru, and Canada. The most important copper ores are the sulfides, oxides, and carbonates. From these, copper is obtained by smelting, leaching, andby electrolysis. Its alloys, brass and bronze, long used, are still very important; all American coins are now copper alloys; monel and gun metals alsocontain copper. The most important compounds are the oxide and the sulfate, blue vitriol; the latter has wide use as an agricultural poison and as analgicide in water purification. Copper compounds such as Fehling’s solution are widely used in analytical chemistry in tests for sugar. High-puritycopper (99.999 + %) is available commercially. Natural copper contains two isotopes. Twenty five other radioactive isotopes and isomers are known. 1

•&nbsp"Copper is so widely used, especially in its alloys such as bronze (Cu and Sn) and brass (Cu and Zn), that it is becoming very scarce...The increased use of fiber optics in place of copper in communications cables may help to lessen the demand for this metal. The use of superconducting materials in electricity transmission lines could eventually provide enormous savings." 2
•&nbsp"hemoglobin, bone, nerves, vascular system...needed for the absorption and mobilization of iron, so a deficiency of copper causes a type of anemia that is difficult to distinguish from iron deficiency anemia. Copper is also needed for the cardiovascular system, bone, brain, and nervous system. Premature and malnourished infants are particularly susceptible to developing copper deficiency, in part because milk is a poor source of copper." 3
•&nbsp"One of the many important uses of copper is to make wire for electric transmission. For this it must be practically pure, as even very small amounts of impurity lower the conductivity. If the conductivity of pure copper is considered as 100, copper containing 0.8 per cent of arsenic has a conductivity of only 30, and copper containing 0.5 per cent of silicon has a conductivity of 28. The electrolytic refining of copper furnishes metal pure enough for most electrical work. Sheet copper is used extensively for roofing, linings, and ornamental work. The copper sheeting in the Statue of Liberty is estimated to weigh about 20,000 pounds. Copper is also an important constituent of the bronzes and brasses." 4

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